The deal, which will mean over $:1 billion ($1.84 billion) in orders for the British aircraft industry, assures the Harrier jump-jet a life well into the 1990s. It also means that a form of modern technology devised over 20 years ago is at last reaching the point of major fulfillment.

First-generation Harriers began flying in the 1960s amid predictions that the plane's vertical short takeoff land landing (VSTOL) capability would revolutionize combat aircraft.

But then doubts and hesitations set in. The Harriers had only limited range. The payload they could carry was also restricted.

British planemakers tried to devise a version of the jump-jet that could carry more bombs and might be better able to defend itself against attacking aircraft.

In the end, many of these hopes fell by the wayside, and the British Defense Ministry decided to cooperate with the US on development of a joint-venture plane. The result is the AV8B, which will be flown by the US Marines and the RAF.

The new plane will be faster and safer than the AV8B now in service with the Marine Corps. It will also carry an effective antitank gun, making it a deadly weapon against armored formations.

Under the joint deal, 60 percent of the airframe work will be done by the US firm McDonnell-Douglas; 75 percent of the work on the plane's Pegasus VSTOL engine will go to Rolls-Royce.